The present invention relates to gas-purifying devices.
In particularly, the present invention relates to a device for removing solid and/or gaseous components present in a flowing gas, the device of the invention including a cyclone separator for separating relatively coarse solid components from the gas, while relatively fine solid components and/or gaseous components present in the flowing gas are separated therefrom by wet-washing.
As is well known, flowing gas streams often contain relatively large amounts of solids and, in addition, for example, sulphur dioxide or other gaseous components which are harmful to the environment or which for certain reasons should be recovered from the flowing gas. The relatively coarse solid components can easily be separated from the flowing gas by using devices such as, for example, cyclone separators, of which numerous different designs are well known. It is possible with certain cyclone separators to achieve a very high separating efficiency, but gaseous components cannot be separated with such cyclone separators.
Thus, in connection with removal of gaseous components, wet-washing or scrubbing is often the only possible way for removing such components from a flowing gas. However, wet-washers often do not tolerate loading with a high degree of solid matter, and on the other hand the solids may be valuable in their dry state, so that wet-washing alone is not always the best possible way to purify a flowing gas. As a result, in the separation of certain components from a flowing gas it is common to encounter in the separating apparatus the combination of a cyclone separator followed by a wet-washer or scrubber, with the separate separation steps being performed in these separate units. As a result, an apparatus of the latter type has an undesirably large size and requires considerable amounts of energy, because both of the separate separating steps have their own pressure losses. Leakage of the flowing gas, wear and tear of the apparatus, and difficulties resulting from the temperature of the flowing gas are further drawbacks which are encountered with conventional apparatus of the above type.
Various attempts have been made to eliminate the above drawbacks resulting from the combination formed by a separate cyclone separator and a separate wet-washer. At the present time it is common to use dry filters particularly in order to separate mechanical dust from a flowing gas. In dry filters a suitable construction is utilized in order to conduct both the coarse and the fine solid components in a flowing gas to the separating unit. On the other hand, it is not possible with dry filters to separate the gaseous components from the flowing gas. Therefore, with respect to such gaseous components it is still necessary to utilize a separate wet-washing procedure, and thus dry filters alone cannot completely purify the flowing gas.